All About Battery Chargers

Here you can learn all in's and out's of battery chargers ...read moreCommon Charging Types:

On-board battery chargers are battery chargers that are mounted to the boat. These chargers use an AC power source (most commonly a standard wall-outlet in the garage or shorepower station), with the charger transferring the power into the DC current your batteries need

Battery Maintainers & Trickle Chargers are terms used to describe a battery charger that provides a slow and steady charge. The most common use of these chargers are to prevent a battery from dying when it's not in use for extended periods of time.

Charging Relays are used to route and manage alternator generated current. Charging relays also have 'battery isolators', which isolate the charges to each battery (circuit). Battery Isolators have the same function as charging relays, but usually don't include the management of the alternator-generated current.

Battery to Battery Chargers are devices used to transfer current from one battery to another

Battery Banks: Each battery you charge will connect to one of the battery chargers banks. If you need to charge 3 batteries at one time, you will need a battery charger with a minimum of three banks. It's a good idea to get a charger with the number of banks you foresee yourself using during the lifetime of the battery charger.

Output voltage rating: Most Battery Chargers are rated for 12v batteries, though 24, 36v, and 48v are not uncommon. Some battery-chargers have the ability to charge multiple ratings of batteries. Simply choose an option that is rated for your batteries voltage rating.

Input voltage ratings: Voltage ratings are measured in ranges, but tend to revolve around 120v and 220-240v, the most common voltage outputs world wide. In North America, you'll want to pick an option that includes 120v in it's range. Many Chargers are rated to cover AC out put worldwide (100-250v); a wise choice for the avid traveler

Amperage rating: Higher amp ratings will mean a faster charge, and are commonly rated by total amps, using the sum of amps provided per bank. For example, a 3-bank charger that provides 5 amps per a bank is rated at 15 amps total. However, not all banks have the same output. For example the ProMite on-board battery charger by ProMariner includes an option that provides a total of 13amps using three banks; 2x banks are rated at 5amp, 1x bank is rated at 3amps. This would commonly be written out as '5/5/3'

Battery compatibility: Make sure to pick a battery charger that is compatible with your type of battery. Most chargers will work with standard lead-acid (wet cell) batteries and some chargers are compatible with almost all battery types used in the marine industry. Regardless, verify the charger is compatible with your battery type.

Features: There are many features to pick from when selecting a battery charger. Most will come standard with an automated 3-stage charging system to provide efficient charge & prevent over-charging, as well as feature a rugged construction designed to withstand the ruggedness marine environment.

***Notice the 'Refine Search' feature on the sidebar. It will allow you to quickly filter down to the product options that will work for your boat's needs and spend more time on price and feature comparisons.

Having a reliable Battery Charger that's designed for your application is one of the most important factors in establishing and maintaining a safe and reliable boat. This makes getting ar reliable battery charger equipped to meed the needs and specs of your boat fundamental. We've tried to make finding the perfect battery for your boat easy buy offering only industry-recognized brands such as Guest, Promariner, Minn Kota, Charles, PowerFilm, and Mastervolt. Additionally, our Refine Search side-bar makes it easy to find the battery you needs in regards to voltage, number of banks, brands, charger type, and amps. Lastly, be confident with our Low Price Guarantee that you'll be getting the best price on the charger you decide to go with.

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Blue Sea Systems Tech Tip: Charge Coordination Explained

Here you can learn how charge coordination works with our Tech Tip's thorough explanation. ...read more

When charging batteries, the alternator plays the smallest part in the process. The alternator fulfills its duties in charging the battery, but the AC battery charger will maintain the charge. As the AC battery works to maintain the charge, this three-step charging stage must take place.

Bulk Charge

Bulk charge is a charge form that sends currents to batteries at the highest and safest capacity rate. It will accept voltage charges up to between 80 and 90%. The voltage amount usually ranges between 10.5 volts and 15 volts. Depending on the application, there might be limits on the maximum current that can be applied.

Absorption Charge

Absorption charge is the stage where voltage levels tend to remain the most consistent and then eases into an internal resistance that increases as it charges. The voltages will usually have risen to 14 to 15 volts.

Float Charge

The batteries, at this point, will have reached full capacity. The voltages will decrease their levels between 12 and 13 in order to prolong the life of the battery. Then a process known as pulse width modulation (PWM) takes control, in which, it seeks out tiny voltage drops in the battery and sends out short charging cycles to the battery. By the end of this stage, the voltage should be maintained at a level between 13.02 and 13.20 volts.

Blue Seas P12 Battery Charger (Video)

Video Transcript

You know as boats becoming increasing more complicated, their battery banks get larger and larger. And with the new chemistries of batteries you get more reliable batteries but at a higher cost.

To solve your battery management problems, Blue Sea Systems has introduced the P12 chargers, available in a 25 amp or for larger vessels of 45 amp bottle.

These are pre-programmed for the four most common chemistries of batteries; flooded lead acid batteries, gel batteries, AGM batteries and TPPL batteries.

So built inside of this is the logic to precisely charge those batteries that both the bulk, absorption float stages. But Blue Sea Systems has gone one stage further; they actually have the fourth stage which they call “pre-float”.

You know most battery chargers will take their full output and put it into the batteries which we call “bulk”. They reach a certain voltage and then they taper off the ampere overtime without overcharging during absorption.

But if you have batteries of different sizes, say a large house bank and smaller starting battery bank; the large house bank may not be fully charged but the starting batteries had enough.

The P12 charger has the smarts to lower the voltage on the smaller banks of batteries, what we call pre-float and hold them at that voltage which is non-injurious until all the batteries are charged and then drop it down to float. This can greatly increase the lifetime of smaller batteries so that they’re not overcharged during a normal charge cycle.

And you know, with the development of these new battery chemistries, a lot of the battery manufacturers have very specific recommended charge voltages and they may not be exactly what the pre-set voltage sets. So the P12 charger is actually fully customizable. You can set the absorption voltage, the float voltage and the amount of time spent in absorption to perfectly match your battery manufacturer’s recommendations.

So rather than going with the generic setting, if you want, you can reset it to a custom setting to absolutely optimize your battery charging.

To maximize the performance and lifetime of your batteries, the P12 charger is a great choice. It’s designed, assembled and tested in the United States and it’s backed by Blue Sea Systems Industry leading 5 year warranty. read less